THE APTERYGOTES
Order PROTURA
(Protos=first; uros=tail)
(Ex. Telson-tails, Acerantomon)
This order includes 90 species. They are minute insects with somewhat depressed, soft white bodies, with prognathous head and without eyes. Antennae are also absent. They are primitively wingless, with reduced prothorax. Tarsus is one-segmented. Abdomen is 11-segmented, with telson (that is why called telson-tails) but without cerci. Fore legs have sensory function.
Telson-tails have worldwide distribution. They are found in damp and dark places, in decaying matter, in debris, under bark, stones or in leaf-litter and are photophobous. They can be collected by touching with a damp brush and preserved in 80% alcohol. Later they can be mounted on slide in polyvinyl lectophenol, since it has a high refractive index.
Order DIPLURA 
(Diplos=double; uros=tail)
(Ex. Campodea and Japyx)
They are herbivores or predaceous, found in damp, dark situations among dry leaves, dead wood or under stones where they feed on fungus or other matters.
This is a small group having about 400 species worldwide.
They have prognathous head without compound eyes or ocelli and with long moniliform antennae. Mouthparts are mandibulate type. They are primitively wingless. Tarsi one or two segmented. Cerci are two long moniliform as in campodeids or short pincer-like as in japygids. Size 1-2 mm.
Order Collembola
(Kolla=glue; embolon=peg)
(Ex. – Springtails and snow fleas)
Minute, soft bodied insects, 2 mm long, dull whitish in colour. Head prognathous. Compound eyes with 8 facets. Ocelli absent. Antennae 4-6 segmented, filiform. Maxilla and labium reduced. One-segmented tarsus is fused with tibia. Abdomen 5-segmented with a telson, which is modified to form a springing organ. The Furcula is a forked springing organ on the 2nd and 3rd abdominal segments. It can jump about 3 inches high with the help of furcula. Cerci never present. Their food consists of decaying matter in damp soil.
They are found in decaying matter, in damp places, in debris and can be extracted with Berlese funnel or collected with aspirator or a camel hair brush dipped in alcohol. They are preserved in 80% alcohol and mounted on slide.
Order Thysanura
(Thysanos=bristle; uros=tail)
(Ex. – Bristle-tails; silverfish, Lepisma)
The order includes about 350 species. Insects have soft elongated bodies covered with silvery scales. Prognathous head with compound eyes and with or without ocelli. Antennae long, multisegmented, filiform. Mouthparts biting and chewing type. Tarsi 2-4 segmented. Cerci long and multisegmented, filiform, usually three. They are primitively wingless insects.
They are found in a variety of habitats, usually in damp and dark places. Silverfish are found on the walls in houses, behind the pictures and books. They are omnivorous and prefer starchy material. Many are found in debris and can be extracted by Berlese funnel and can be picked with aspirator or with a brush dipped in alcohol. Preserve in 80% alcohol, with pieces of tissue paper to prevent shaking. Small specimens can be mounted on slide.
For Exopterygota click Next